It is known, from French patent specification FR 2 514 105 of the Company Valeo Vision, to provide a headlight which a light guide consists of a single transparent barrel arranged horizontally and transversely to the direction of emission, with the front of the barrel having a vertical outlet face for emitting light, and the rear of the barrel including a set of cut-outs of limited height defining a series of oblique reflective facets. These facets are disposed in an optical cooperating relationship with lenses having an axis parallel to the emission direction, so that the lenses project images corresponding to the facets in that direction.
Such a headlight, however, have the disadvantage that it is not possible to control the quantity of light flux arriving at each of the facets of the single optical barrel, because of the multiple reflections of the light rays within the latter. In this regard, because of the uncontrollable multiple reflections of the light rays within the barrel, it can happen that one or more facets of the barrel are very weakly illuminated. A consequence of this is that the quality of the final light beam is altered.
In addition, in such a headlight, no mounting means is provided for ensuring accurate positioning of the oblique reflective facets and of the output face of the light guide with respect to the lenses, such that the latter will project, in the emission direction, images corresponding to the facets at a predetermined position, despite the dispersions of light within the thickness of the transparent barrel. In addition, no means is provided for ensuring accurate positioning of the input face of the light guide with respect to the light source itself.